org.apache.lucene.util.automaton
Class State

java.lang.Object
  org.apache.lucene.util.automaton.State

All Implemented Interfaces:

Comparable<State>

public class State
extends Object
implements Comparable<State>

Automaton state.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

int	numTransitions
Transition[]	transitionsArray

Constructor Summary

State()
Constructs a new state.

Method Summary

void	addTransition(Transition t) Adds an outgoing transition.
int	compareTo(State s) Compares this object with the specified object for order.
int	getNumber() Return this state's number.
Iterable<Transition>	getTransitions() Returns the set of outgoing transitions.
int	hashCode()
boolean	isAccept() Returns acceptance status.
int	numTransitions()
void	reduce() Reduces this state.
void	setAccept(boolean accept) Sets acceptance for this state.
void	setTransitions(Transition[] transitions)
void	sortTransitions(Comparator<Transition> comparator) Sorts transitions array in-place.
State	step(int c) Performs lookup in transitions, assuming determinism.
void	step(int c, Collection<State> dest) Performs lookup in transitions, allowing nondeterminism.
String	toString() Returns string describing this state.
void	trimTransitionsArray() Downsizes transitionArray to numTransitions

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

transitionsArray

public Transition[] transitionsArray

numTransitions

public int numTransitions

Constructor Detail

State

public State()

Constructs a new state. Initially, the new state is a reject state.

Method Detail

getTransitions

public Iterable<Transition> getTransitions()

Returns the set of outgoing transitions. Subsequent changes are reflected in the automaton.

Returns:

transition set

numTransitions

public int numTransitions()

setTransitions

public void setTransitions(Transition[] transitions)

addTransition

public void addTransition(Transition t)

Adds an outgoing transition.

Parameters:

t - transition

setAccept

public void setAccept(boolean accept)

Sets acceptance for this state.

Parameters:

accept - if true, this state is an accept state

isAccept

public boolean isAccept()

Returns acceptance status.

Returns:

true is this is an accept state

step

public State step(int c)

Performs lookup in transitions, assuming determinism.

Parameters:

c - codepoint to look up

Returns:

destination state, null if no matching outgoing transition

See Also:

step(int, Collection)

step

public void step(int c,
                 Collection<State> dest)

Performs lookup in transitions, allowing nondeterminism.

Parameters:

c - codepoint to look up

dest - collection where destination states are stored

See Also:

step(int)

trimTransitionsArray

public void trimTransitionsArray()

Downsizes transitionArray to numTransitions

reduce

public void reduce()

Reduces this state. A state is "reduced" by combining overlapping and adjacent edge intervals with same destination.

sortTransitions

public void sortTransitions(Comparator<Transition> comparator)

Sorts transitions array in-place.

getNumber

public int getNumber()

Return this state's number.

Expert: Will be useless unless Automaton.getNumberedStates() has been called first to number the states.

Returns:

the number

toString

public String toString()

Returns string describing this state. Normally invoked via Automaton.toString().

Overrides:

toString in class Object

compareTo

public int compareTo(State s)

Compares this object with the specified object for order. States are ordered by the time of construction.

Specified by:

compareTo in interface Comparable<State>

hashCode

public int hashCode()

Overrides:

hashCode in class Object